Hearing instruments are in common use today and usually include a microphone circuit, amplification circuit, and receiver (or speaker) circuit. The microphone circuit receives audio energy and then converts this audio energy into electrical signals. The electrical signals may, in turn, be amplified (or otherwise processed) by the amplification circuit and forwarded to the receiver. The receiver circuit may then convert the amplified signals into audio signals that the user of the hearing instrument can hear. Other electronic devices may also utilize the above-mentioned circuits. Receivers and speakers are useful in many listening devices such as earphones, headphones, Bluetooth wireless headsets, or the like.
Generally speaking, conventional receiver in canal (RIC) devices are designed to isolate the desired sound presented at the user's ear drum from other sounds and/or noise from the outside environment above a particular frequency (e.g., approximately 1 kHz). In this regard, previous insert earphones typically included a housing having a receiver mounted within the housing. A rigid ear tip surrounded the housing and engaged the walls of the ear canal. In these systems, the receiver was positioned near the entrance to the ear canal so that the user could receive the sound energy produced by the receiver.
Currently, hearing instrument users are attempting to extend the bandwidth of their instruments to improve the sound quality experienced by the end user. Unfortunately, several problems existed with the current approaches. Customers are expanding the frequency range in both low and high frequencies. A high frequency driver typically does not have sufficient output in low frequencies when in open fit applications. For low frequency operations, a seal is used for a balanced armature receiver to provide sufficient output to the user. However, when the ear is sealed, the user experiences poor sound quality due to occlusion. This has produced user dissatisfaction with these previous approaches.
Those of ordinary skill in the art will appreciate that elements in the figures are illustrated for simplicity and clarity. It will be further appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those of ordinary skill in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.